I have my home server apps configured with NGINX proxy manager and DuckDNS to access remotely, but about three weeks ago DuckDNS URLs stopped working on my home network. I can access 192.168.XXX.XXX:1234 on the home network but myapp.duckdns.org times out.

It DOES work as expected using a VPN or on mobile data.

Any ideas as to what’s going on?

EDIT: I kind-of sort-of got a workaround working using pi-hole “local DNS” feature to point the duckdns URL to NGINX. Didn’t work

EDIT 2: Disabling the router’s firewall completely seems to have fixed it. Still trying to figure out the exact setting that did it. I will update this post if I can.

  • Dangerhart@lemm.eeEnglish
    1·
    8 hours ago

    Are you using your router as DNS and DHCP? With Verizon I had a security setting that was blocking public DNS entries to resolving to local addresses. I can’t remember what it’s called, but it’s to prevent a certain type of attack. For a while I disabled it but switching to pihole as DNS, DHCP and using unbound solves it without the security implications

  • CmdrShepard42@lemm.eeEnglish
    1·
    23 hours ago

    I don’t know if this will be of any help, and I dont fully understand the intricacies, but I run into similar issues with my HomeAssistant setup when the certificates expire (every couple of months?). The issue is that HA doesn’t pull the new certificate without a reboot, so I typically just restart it every once in a while to ensure that it has the newest certificate.

    • Jediwan@lemy.lolOPEnglish
      2·
      22 hours ago

      Thanks, but I don’t think that’s it. I rebooted and also tried adding a new container to NGINX with a DuckDNS url and it won’t load on the local network.

  • PerogiBoi@lemmy.caEnglish
    4·
    1 day ago

    I had the exact same issue. My troubleshooting took me to my router. Nat Loopback and hair pinning.

    Your router might have some options relating to NAT loopback or hairpinning. Apparently this can happen if your router recently had an update or if it was restarted abruptly and didn’t boot properly.

    Try restarting your router. It didn’t work for me and my router is too basic for those options so in the end I took down my Nextcloud and remade another container and started from scratch. I had all sorts of things fucked with my instance so it just made sense to toss it out and fix it again.

    Hope it works for you!

    • Jediwan@lemy.lolOPEnglish
      3·
      1 day ago

      Thanks for the response but restarting the modem/router didn’t change anything, nor did creating a new container/NGINX config.

    • Jediwan@lemy.lolOPEnglish
      3·
      1 day ago

      Yes and DuckDNS is working flawlessly everywhere except that the network the server is also connected to.

      • Lyra_Lycan@lemmy.blahaj.zoneEnglish
        2·
        1 day ago

        Sometimes DuckDNS goes down partially, their servers breaking for about a week is why I purchased a domain and now host via Cloudflare.

        Edit: One of my DuckDNS domains works internally, so at least it’s not a systemwide issue. Perhaps one of their relays…

    • Jediwan@lemy.lolOPEnglish
      1·
      1 day ago

      Arris G36 but I don’t believe that’s the issue as it was working for years before now and on a different router too.

      • tychosmoose@lemm.eeEnglish
        2·
        1 day ago

        Could also be a stale DNS cache entry on one device or the router. If you ping your duckdns fqdn from the device that can’t connect while on your home network, does it resolve to the correct public IP?

        I still think a firewall/nat issue is more likely tho.

        • Jediwan@lemy.lolOPEnglish
          2·
          1 day ago

          Hm, pinging works and shows my (external) IP. But no device I’ve tested can load the duckdns URL.

          EDIT: Two of the URLS show the local IP replying when pinged. Not configured any differently so I’m not sure what’s going on there. This was a PiHole thing apparently

  • enemenemu@lemm.eeEnglish
    2·
    1 day ago

    I’ve got the same problem since a month or two with another dyndns provider. That’s not specific to the dydns provider. It is the router. Yet I have no idea how to fix it, and I am too lazy currently.

    I’m on graphene, btw.